The trend in packaging of electronic circuits fueled by integrated circuits has led to center spacings between circuit paths, traces, and contacts being reduced many times over. Thus, center-to-center spacings of 0.150 inches have been halved and halved again until center spacings of 0.025 inches are demanded. These relatively small dimensions require relatively small electrical contacts, housings, and assembly techniques; the very smallest increasing the cost of manufacturing tooling, jigs, fixtures, and the like. The ability to reduce the trace and contact pad sizes on circuit boards, which is done essentially by lithography, has proven to be less of a problem that the manufacture of associated connectors which are formed by traditional tools and techniques and carry tolerances inimicable to the present design trends of spacing dimensions.
A number of U.S. Patents purport to deal with the problem and one such is U.S. Pat. No. 4,869,672. In that patent, a circuit board connector, sometimes called a card edge connector, utilizes a double row of contacts staggered to provide very close centers in a linear sense along the length of the connector. The patent teaching is to provide interconnection of conductive pads on different centerline spacings as between a daughter board plugged into the connector and the mother board upon which the connector rests. The contacts of the connector end in spring fingers engaging the conductive pads on the daughter board on one end and on the other end in tabs which are plugged into the holes of a circuit board and soldered thereto The connector is manufactured by traditional methods in that the contacts are stamped and formed and then assembled into a molded housing.
An object of the present invention is an improved method of manufacture for electrical connectors having close centerline spacings and high numbers of contacts therein.
A further object of the invention is the provision of manufacturing electrical connectors in a way that assures accurate spacing of the contacts thereof in multiple in a low cost manner.
The invention has as a still further object of the provision of an electrical connector utilizing either drawn wire for contacts or stamped contacts trimmed, formed, and insert molded in multiple to provide a connector assembly.